Exam 2: Kinematics in One Dimension

A test rocket is fired straight up from rest with a net acceleration of 20.0 m/s².After 4.00 seconds the motor turns off,but the rocket continues to coast upward with no appreciable air resistance.What maximum elevation does the rocket reach?

A rock is thrown directly upward from the edge of the roof of a building that is 66.2 meters tall.The rock misses the building on its way down,and is observed to strike the ground 4.00 seconds after being thrown.Neglect any effects of air resistance.With what speed was the rock thrown?

The figure shows the graph of the position x as a function of time for an object moving in the straight line (the x-axis).Which of the following graphs best describes the velocity along the x-axis as a function of time for this object?

The figure represents the position of a particle as it travels along the x-axis.Between t = 2 s and t = 4 s,what is (a)the average speed of the particle and (b)the average velocity of the particle?

A ball is thrown directly upward and experiences no air resistance.Which one of the following statements about its motion is correct?

A rocket takes off vertically from the launchpad with no initial velocity but a constant upward acceleration of 2.25 m/s².At 15.4 s after blastoff,the engines fail completely so the only force on the rocket from then on is the pull of gravity. (a)What is the maximum height the rocket will reach above the launchpad? (b)How fast is the rocket moving at the instant before it crashes onto the launchpad? (c)How long after engine failure does it take for the rocket to crash onto the launchpad?

The motions of a car and a truck along a straight road are represented by the velocity-time graphs in the figure.The two vehicles are initially alongside each other at time t = 0.At time T,what is true about these two vehicles since time t = 0?

A ball is projected upward at time t = 0.00 s,from a point on a roof 70 m above the ground and experiences negligible air resistance.The ball rises,then falls and strikes the ground.The initial velocity of the ball is Consider all quantities as positive in the upward direction.The velocity of the ball when it is above the ground is closest to

A package is dropped from a helicopter moving upward at If it takes before the package strikes the ground,how high above the ground was the package when it was released if air resistance is negligible?

On the earth,when an astronaut throws a 0.250-kg stone vertically upward,it returns to his hand a time T later.On planet X he finds that,under the same circumstances,the stone returns to his hand in 2T.In both cases,he throws the stone with the same initial velocity and it feels negligible air resistance.The acceleration due to gravity on planet X (in terms of g)is

A car starts from rest and accelerates with a constant acceleration of 1.00 m/s² for 3.00 s.The car continues for 5.00 s at constant velocity.How far has the car traveled from its starting point?

A speeding car is traveling at a constant 30.0 m/s when it passes a stationary police car.If the police car delays for 1.00 s before starting,what must be the magnitude of the constant acceleration of the police car to catch the speeding car after the police car travels a distance of 300 m?

A foul ball is hit straight up into the air with a speed of 30.0 m/s. (a)Calculate the time required for the ball to rise to its maximum height. (b)Calculate the maximum height reached by the ball. (c)Determine the time at which the ball pass a point 25.0 m above the point of contact between the bat and ball. (d)Explain why there are two answers to part (c).

A rock is dropped from the top of a vertical cliff and takes 3.00 s to reach the ground below the cliff.A second rock is thrown vertically from the cliff,and it takes this rock 2.00 s to reach the ground below the cliff from the time it is released.With what velocity was the second rock thrown,assuming no air resistance?

The position of an object as a function of time is given by where and (a)Find the instantaneous acceleration at t =2.4 s. (b)Find the average acceleration over the first 2.4 seconds.

A soccer ball is released from rest at the top of a grassy incline.After 8.6 seconds,the ball travels 87 meters and 1.0 s after this,the ball reaches the bottom of the incline. (a)What was the magnitude of the ball's acceleration,assume it to be constant? (b)How long was the incline?

Arthur and Betty start walking toward each other when they are 100 m apart.Arthur has a speed of and Betty has a speed of Their dog,Spot,starts by Arthur's side at the same time and runs back and forth between them at 5.0 m/s.By the time Arthur and Betty meet,what distance has Spot run?

Suppose that a car traveling to the west (the -x direction)begins to slow down as it approaches a traffic light.Which statement concerning its acceleration in the x direction is correct?

An object is moving with constant non-zero acceleration along the +x-axis.A graph of the velocity in the x direction as a function of time for this object is